I have about 3k miles on a new motor and 250k on the chassis and who knows about the trans history. I was driving in my econo tune (gearhead tunes) they always shift hard and fast and dont like alot of throttle in the lower gears. I throttled today in the top of first and it just sat at the rev limiter and wouldnt shift. I let off the throttle and it felt ok afterwards and all was fine. Later that day it was taking forever to shift into second and didnt hit as hard when it does, also it is down shifting way more when it would have just stayed in second normally and takes a lot of rpm to shift. It is worse in my higher tunes.

The fluid is overdue and is kinda ruff, wouldnt say its burnt but its for sure not normal I know that much.

Being that I have an early 99 it shouldnt have the mechanical diode but after all the reading it kinda sounds like the same issue / symptoms.

Does anyone who has been down this road have any input on my situation, I know BTS but after 15k + on this build its tuff to tell the wife I need another 6k.

 

anyone have anything similar or know if I should just change the fluid right away or pull it out?

 

Before pulling the trans I'd check for codes. The problem might not be in the transmission. And Ford didn't build any 4R100 transmissions with a mechanical diode until Job#1 2001.

 

Thanks Mark I was hoping you would see this. I will have it scanned and report back.

 

Ok so after a day of not driving the truck heres what happened. On the way to workfr cold it shifted just fine, after 20 miles or so it started lagging again in the 1-2 shift, all other gears were fine.

On the way home to the trans shop it was the same except for when it went for 3rd it grabbed and had major friction, I let off right away. Coasted to first gear speed and gave it gas again, 2-3 same thing as if it was compression braking but it wasnt from the engine, no grinding or mechanical sounds.

I put the shifter into second and there was no issue and limped to the shop.
The owner plugged in the scanner, zero codes, pump pressure a little lower than he would like at idle but that might just be the old fluid.

He test drives it only to confirm what I was experiencing, he then cycled the overdrive button and it all went away.

He thinks that the solinoid pack has a piece of debris that is making the valve/plunger hang up off and on and is not allowing the spagg to disengage and the coast clutches are locking up as a result.

With that logic he said that the solinoids can be flushed and cleaned carefully and he will do a full service flush while the pan is off and that it should take care of the issues.

Mark does that sound about right to you? A

Much appreciated.

 

That sounds like a very good shop. A lot of national chain shops would try to sell you a rebuild.

 

This guys integrity is so good, he took the time to show me a soliniod pack and how it worked, the spragg and mating parts and how they are reacting in my truck with actual 4r100 parts. Then after I made the appointment I realized I would be unable to get home, he says dont worry I live 15 minutes away from you and I can give you a lift. Now thats service!

 

I think he knows what he is doing.

 

That's sounds like good news thanks!

 

Heres my update, get the pan off change the filter and clean the solinoids. Everything seems ok other than the clutch material in the pan (although its been sitting for 6 years until recently) filter has some stuff but nothing major.

Leave the shop the trans feels stronger right away with the new fluid. Next day doing some light off roading I throttled fairly hard, not pinned but 3/4 and it just moved slow but on the rev limiter.

I get back on the road and then I loose 1 and 2 gear. I limp it home, get nearly there and get frustrated and throttle it and it slammed down back into first and has been working since.

I starter thinking the worst, call the shop and he seemed to think the plunger in the valve body got stuck?

So today I drive it and still 1st gear takes a lot of rpm to shift (might throw in a abs sensor in the diff to see if that helps as its cheap) and if you drive it real easy its good, at any speed below 50mph you go from 3-2 it just sits on the rev limiter and disengages completly. If you do the same throttle from 1-2-3-4 its ok.

What the heck is going on, I would love to just go buy the BTS but the cash isnt there right now, any clues guys? Much appreciated if you took the time to read this!

Todd

 

Take it back to the shop. The tech there is probably correct.